Hi Rob, Thanks for the reply.
On Wed, Sep 20, 2017 at 03:53:13PM -0500, Rob Herring wrote: > On Mon, Sep 18, 2017 at 11:25:04AM +0300, Sakari Ailus wrote: > > A lot of devices do not need and do not document port or endpoint > > numbering at all, e.g. in case where there's just a single port and a > > single endpoint. Whereas this is just common sense, document it to make it > > explicit. > > > > Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com> > > --- > > Documentation/devicetree/bindings/media/video-interfaces.txt | 12 > > ++++++++++++ > > 1 file changed, 12 insertions(+) > > This is fine, but bindings should still be explicit. Otherwise, I'm > wondering if it's a single port/endpoint or they just forgot to document > it. And I shouldn't have to look at the example to infer that. > > Acked-by: Rob Herring <r...@kernel.org> The purpose of the patch was to actually document port and endpoint numbering for devices for which it is not documented, not to suggest that this would be omitted in in binding documentation. The fact is that I couldn't find documentation for endpoint numbering for a single device under Documentation/devicetree/bindings/media/ . Yet I haven't come across DT source where other than zero would have been used. And the drivers (mostly?) have ignored endpoint numbers so far. Some bindings have been omitted on the grounds that they're documented in video-interfaces.txt. What would you think of the following? I'm not sure it'd really belong there, but it'd be a small piece of documentation one can easily refer to. >From e735979005244eb10597fe5333130b93e41d5a38 Mon Sep 17 00:00:00 2001 From: Sakari Ailus <sakari.ai...@linux.intel.com> Date: Mon, 18 Sep 2017 11:15:53 +0300 Subject: [PATCH 1/1] dt: bindings: media: Document practices for DT bindings, ports, endpoints Port and endpoint numbering has been omitted in DT binding documentation for a large number of devices. Also common properties the device uses have been missed in binding documentation. Make it explicit that these things need to be documented. Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com> --- .../devicetree/bindings/media/video-interfaces.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt index 852041a..3c5382f 100644 --- a/Documentation/devicetree/bindings/media/video-interfaces.txt +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt @@ -55,6 +55,21 @@ divided into two separate ITU-R BT.656 8-bit busses. In such case bus-width and data-shift properties can be used to assign physical data lines to each endpoint node (logical bus). +Documenting bindings for devices +-------------------------------- + +All required and optional bindings the device supports shall be explicitly +documented in device DT binding documentation. This also includes port and +endpoint numbering for the device. + +Port and endpoint numbering +--------------------------- + +Old binding documentation may have omitted explicitly specifying port and +endpoint numbers. This often applies to devices that have a single port and a +single endpoint in that port. In this case, the only valid port number for such +a device is zero. The same applies for devices for which bindings do not +document endpoint numbering: only zero is a valid endpoint. Required properties ------------------- -- 2.7.4 -- Sakari Ailus sakari.ai...@linux.intel.com
